Various cartridge-type faucet valves have heretofore been utilized in wash basins, sinks, bath tubs, showers, faucets and the like for controlling flow from a supply of hot and/or cold water. Such faucet valves characteristically have a valve housing or body forming a relatively permanent part of a given installation and a removable or replaceable faucet valve insert assembly, or cartridge, which is inserted into and assembled with the housing to form a complete faucet valve. A cartridge typically includes a valve seal and seat, which cooperate to provide the flow control (or the on-off action of the faucet valve) and a mechanism for controlling the faucet valve position (i.e., seal and/or seat positions) in response to an actuation of the valve, manually or otherwise. The mechanism typically includes a movable valve stem.
It has been found, however, that certain cartridge-type faucet valves have been beset with sealing problems. In particular, a problem has arisen with a seal between the valve housing and the cartridge itself. Such a seal is often needed to isolate the inlet of the valve housing, which may be under constant pressure, from the outlet, which provides the controlled flow (or no flow if the valve is closed). In prior valves, that seal has been provided by the physical abutment of a relatively incompressible (e.g. metal) portion of the cartridge with a relatively incompressible (e.g. metal) portion of the valve housing. As such, a proper seal depended upon maintaining very tight manufacturing tolerances for the mating surfaces and, more importantly, upon field installation or service personnel properly following critical torque limits when tightening the fasteners used for assembling and retaining the cartridge in the housing. This has been costly and has oftentimes resulted in an inferior seal.
A further sealing problem with prior cartridge-type faucet valves involves the seal used to prevent leakage along the valve stem. Heretofore, a retaining nut or the like has been used to hold a packing material against the stem. The packing would permit stem movement yet prevent leakage along the stem. While such an approach can reliably prevent leakage from the valve as a unit, it does nothing to prevent internal leakage from the fluid flow path within the cartridge to the mechanism of the cartridge used to control valve position. Such leakage can degrade or wash away necessary lubricant from the mechanism and can result in the accumulation of mineral deposits or corrosion within the mechanism, thereby shortening the useful life or the service interval of the valve cartridge.